摘要
利用MTS815试验机进行了不同应力路径下花岗岩峰前卸荷试验,研究了全应力-应变曲线、变形破坏特征和变形参数的劣化规律。数据分析表明：相比加载试验,卸荷岩样破坏突然且剧烈,脆性特征显著;卸荷过程中,轴向应变增量较小,侧向应变增量较大,两者相差5~10倍,轴压围压同时卸载时岩样破坏前轴向应变出现负增长;岩样破坏所需的卸荷量受到卸荷路径的影响,卸围压同时增加轴压时仅需要38%的卸荷量,但脆性特征最明显的是同时卸载轴压和围压。试验结果对不同方式下的岩体开挖具有一定参考意义。
A series of pre-peak unloading tests under different stress path have been carried out with the MTS815 test ma- chine. The complete stress-strain curve, deformation characteristics and degradation law of deformation parameters were stud- ied. Data analysis shows that compared to loading tests, unloading rock is damaged to a sudden and fierce, with obviously brittle characteristics. During the unloading process, the .axial strain increment is small, with great lateral strain increment and the difference between 5 ~ 10 times. Axial strain appear negative growth when axial pressure and confining pressure un- loading at the same time. The rock＇s failure unloading percentage is influenced by unloading stress paths. The unloading per- centage only need to be 38% when unloading confining pressure increase axial compression at the same time. But the brittle characteristics is most obvious when axial pressure and confining pressure are unloaded at the same time. The tests results have some reference significances for the rock mass excavation under different modes.
出处
《世界科技研究与发展》
CSCD
2015年第4期355-358,373,共5页
World Sci-Tech R&D
基金
国家自然科学基金(51374244)资助
关键词
花岗岩
卸荷
应力路径
变形参数
劣化规律
granite
unloading
stress paths
deformation parameter
deteriorating law
